I water cremated (aquamation) my dog and now the ashes turn hard and moldy?

My dog passed away about a year ago. I had him water cremated (aquamation) instead of the regular fire cremation. His ashes came back normal but after a year, they now turned hard and moldy? (Reddish)

The ashes were delivered in a wrapped plastic bag, not sealed. The plastic bag is in a wooden box and the wooden box is wrapped in bubble wrap. The box is in my drawer, with no sunlight.

Is this normal or expected? Should I be worried?